Field of the Invention
The present invention relates to a method for communication control in a communication network, a correspondingly adapted communication control entity, key management entity, terminal and gateway entity.
Recently, mobile communication networks have widely spread and increasingly found attention. In the near future, mobile communication networks will be more and more based on the Internet protocol (IP) so that users may access the Internet by means of the terminals and/or mobile stations MS, exchange data with the Internet or other subscriber terminals, e.g. via the Internet or via IP based networks.
However, even though the subsequent description focuses to a certain extent on IP based networks, the present invention as being subsequently outlined does not require an IP based network to be carried out but may work also with non-IP based networks.
Charging and billing for services offered and used by subscribers in an IP based network are challenging issues, because terminals are intelligent, and end-users are probably able to create their own applications and evade the charging and billing of the network operator (or service provider).
Charging is also problematic in IP based networks because the network is not reliable. This means that as data are transmitted in units of packets such as TCP/IP packets (TCP=Transmission Control Protocol, IP=Internet Protocol), those data packets are often transmitted as “best effort” traffic (even if different qualities of service QoS can be agreed on for such best effort traffic).
If a network operator plans to have charging based on an amount of transmitted data, the IP frame re-sendings, i.e. retransmission of TCP/IP data packets which could not be delivered successfully at the first attempt, in the network can cause more chargeable data than the end-user is able to see. Namely, the subscriber as an end user merely perceives the data necessary for running the application, while retransmissions are transparent to the subscriber.
In future networks, the billing of content (not only data amount but also of “what” is represented by the data) will increase in significance, and also the copyright of the content has to be ensured. To this end, a digital rights management (DRM) system has recently been introduced. DRM systems interact with clearing houses to be able to charge the end-user for the content he used/transmitted.
DRM systems have also been conceived to be used in connection with mobile communication, e.g. for distribution of ringing tones and/or so-called “logos” and/or games to be run as an application on the subscribers' terminals. One such approach is outlined in “Digital Rights Management and Superdistribution of Mobile Content”, White Paper, Nokia, 2001, retrieved on Aug. 22, 2002 from the Internet, i.e. http://www.nokia.com/networks/systems_and_solutions/solution_main/1,23797,423,00.html.
With current solutions, subscribers as well as operators are facing problems such that subscribers may evade the charging and billing of the network operator/service provider; this is not satisfactory for the operator/provider; subscribers may have to pay for retransmitted data packets which they never perceived to have been retransmitted; this is not satisfactory for the subscriber; different billing systems could have to be implemented, e.g. for voice calls or for data transmissions; this is inconvenient for the operator and increases his operational expenses for running the network, while the operator's operational expenses represent already a big portion of operator costs. (It is to be noted that “data” as used herein may also be referred to as “content”, i.e. a payload of data of a specific application for example.)